Method of and system for heat recovery for an internal combustion engine

ABSTRACT

Heat recovery for internal combustion engine, includes introducing a first fluid into heat exchanging element, and withdrawing the heated first fluid from the heat exchanger elements; and supplying at least one second fluid which is used during the operation of the internal combustion engine and is heated, so as to flow outside and in contact with the heat exchanging elements to transfer heat through walls of the heat exchanging element from the second fluid to said first fluid.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to method of and system for heatrecovery for an internal combustion engine.

[0002] Although the efficiency of the internal combustion engine hasbeen improved remarkably in the past 50 years, it is still difficult tooperate such an engine with an efficiency of over 35%. The efficiencydrops off dramatically as an engine ages and may deteriorate to lessthan 10% if it has been improperly maintained. With only 10-35%efficiency, this means that the remaining fuel consumption creates heatwhich therefore is largely unused or produces un-combusted and partiallycombusted fuel which generates no work or heat energy and createsenvironmentally unfavorable compounds. Thus, the waste heat frominternal combustion engines is considerable and is not being usedconstructively. Some solutions directed to this objective are disclosedfor example in U.S. Pat. Nos. 4,378,336; 5,035,867; 5,250,489;5,711,071; 5,869,011; 5,987,885; 6,039,913; and Canadian patents 2184632and 2247759. It is believed that the use of heat in the internalcombustion engine can be further improved.

SUMMARY OF THE INVENTION

[0003] Accordingly, it is an object of the present invention to providean improved method of and system for heat recovery for an internalcombustion engine.

[0004] In keeping with these objects and with others which will becomeapparent hereinafter, one feature of the present invention resides,briefly stated, in a method for heat recovery for an internal combustionengine, which includes introducing a first fluid into heat exchangingelements of a heat exchanger for heating the first fluid, andwithdrawing the heated fluid from the heat exchanger elements; andsupplying at least one second fluid which is used during the operationof the internal combustion engine and is heated, so as to flow outsideand in contact with said heat exchanging elements to transfer heatthrough walls of said heat exchanging elements from said second fluid tosaid first fluid.

[0005] In accordance with another feature of the present invention, thesystem for heat recovery is proposed which has a heat exchangerincluding a plurality of heat exchanging elements; means for introducinga first fluid into said heat exchanging elements for heating in thefirst fluid, and withdrawing the heated first fluid from the heatexchanger elements; and supplying at least one second fluid which isused during the operation of the internal combustion engine and isheated, so as to flow outside and in contact with said heat exchangingelements to transfer heat through walls of said heat exchanging elementfrom the second fluid to said first fluid.

[0006] When the method is performed and the system is designed inaccordance with the present invention, heat produced during theoperation of the internal combustion engine is efficiently utilized.

[0007] The novel features which are considered as characteristic for thepresent invention are set forth in particular in the appended claims.The invention itself, however, both as to its construction and itsmethod of operation, together with additional objects and advantagesthereof, will be best understood from the following description ofspecific embodiments when read in connection with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a view illustrating schematically a method of and asystem for heat recovery for an internal combustion engine;

[0009]FIG. 2 is a view showing a heat exchanger of the inventive system;and

[0010]FIG. 3 is a view showing additional components of the inventivesystem.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A system for heat recovery operates in accordance with aninventive heat recovery method is illustrated in FIG. 1. Referencenumeral 19 identifies an internal combustion engine and referencenumeral 19 a identifies a crankcase of the engine. A lubricant dischargeline 19 b extends from the engine to a heat exchanger and in particularto a heat exchanger area 3 b, while a lubricant return line 19 a extendsfrom the heat exchanger area 3 b back to the engine. A coolant dischargeline 19 g extends from the engine to the heat exchanger and inparticular to the heat exchanger area 3 a, while a coolant return lineextends from the heat exchanger area 3 a to an engine radiator 19 f. Anexhaust gas discharge line 5 extends from the engine to the heatexchanger and in particular to a heat exchanger area 3 c and an exhaustgas discharge line 8 extends from the heat exchange area 3 c toatmosphere.

[0012] The heat exchanger has a plurality of heat exchanging elements(tubes) or a tube bundle 3. A first fluid which can be for example acold water or a motive fluid is introduced into the heat exchangerthrough a first fluid supply line 1 into an interior of the tubes 3, andexits from the tubes 3 through a first fluid discharge line 4. It isthen delivered to a first fluid application area 4 a which can be formedfor example as a turbine which drives a generator. Then, throughdischarge line 4 b it is connected to a fluid pump 4 c which pumps thefirst fluid through the line 1 again into the tubes of the heatexchanger 3.

[0013] The crankcase 19 a is provided with a crankcase vent 23 with avent line 23 a which leads to a venturi 21, which draws the crankcasefumes into the engine exhaust pipe 5.

[0014] During the operation of the internal combustion engine the firstfluid is circulated through the interior of the pipes of the heatexchanger 1 while the second fluid which is a fluid selected from thegroup consisting of the coolant, the lubricant, the exhaust, two ofthese fluids, or all three of these fluids is also supplied to the heatexchanger so as to be in contact with an outer surface of the tubes andto transfer the heat through the wall of the tubes to the first fluidinside the tubes.

[0015] The tubes in the heat exchanger area 3 c can be coated with avariety of catalytic compounds which can cause some of the constituentsof the gas to react with oxygen and in the process release heat. Thecombination of the heat from the exhaust gas and the heat released fromthe catalytic process is transferred through the walls of the heatexchanging elements to the first fluid inside the tubes.

[0016] As shown in FIG. 2, electrically controlled valves 11, 11 a, 11b, 11 c, 11 d are provided for delivery of air and/or fuel through aheat exchanger housing 7 to various heat exchange areas. Theelectronically controlled valves control the flow of air and/or fuel byway of signals sent by a microprocessor 15 through valve control wires13 a, 13 b, 13 c, 13 d, 17 a. This is in response to information fed tothe microprocessor 15 from temperature sensors 12 b, 12 c, 12 d and agas constituent sensor 18 by way of sensor wires 14 b, 14 c, 14 d, 18 a.

[0017]FIG. 3 shows ignitors 12 b, 12 f, 12 h, which are locateddownstream of the valves 11 a, 11 b, 11 c, 11 d. They are activated byan ignition power source 12 after having received the signal to do sofrom the microprocessor 15 through the wire 12 m. The microprocessoractivates the ignitors 12 c, 12 f, 12 g, 12 h in response to signalreceived from temperature sensors 12 b, 12 c, 12 d and the gasconstituents sensor 18, by temperature sensor wires 14 b, 14 c, 14 d andthe gas constituents wire 18 a.

[0018] It will be understood that each of the elements described above,or two or more together, may also find a useful application in othertypes of methods and constructions differing from the types describedabove.

[0019] While the invention has been illustrated and described asembodied in method of and system for heat recovery for an internalcombustion engine, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

[0020] Without further analysis, the foregoing will so fully reveal thegist of the present invention that others can, by applying currentknowledge, readily adapt it for various applications without omittingfeatures that, from the standpoint of prior art, fairly constituteessential characteristics of the generic or specific aspects of thisinvention.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:
 1. A method of heat recovery forinternal combustion engine, comprising the steps of introducing a firstfluid into said heat exchanging elements of a heat exchanger for heatingthe first fluid, and withdrawing the heated first fluid from the heatexchanger elements; and supplying at least one second fluid which isused during the operation of the internal combustion engine and isheated, so as to flow outside and in contact with said heat exchangingelements to transfer heat through walls of said heat exchanging elementto from said second fluid said first fluid.
 2. A method as defined inclaim 1, wherein said supplying the second fluid includes supplying acoolant used during the operation of the internal combustion engine. 3.A method as defined in claim 1, wherein said supplying the second fluidincludes supplying a lubricant used during the operation of the internalcombustion engine.
 4. A method as defined in claim 1, wherein saidsupplying the second fluid includes supplying an exhaust produced duringthe operation of the internal combustion engine.
 5. A method as definedin claim 1, wherein said supplying the second fluid includes supplyingat least two second fluids selected from the group consisting of acoolant, a lubricant and an exhaust of the internal combustion engine.6. A method as defined in claim 1; and further comprising bringing thesecond fluid into a contact with a catalytic material applied on anouter surface of said heat exchanging elements to cause a catalyticprocess and to release heat.
 7. A method as defined in claim 1; andfurther comprising using heat received by the first fluid for creating aheat.
 8. A method as defined in claim 1; and further comprising usingheat received by the first fluid for creating a work energy.
 9. A methodas defined in claim 1; and further comprising withdrawing crank casefumes from the internal combustion engine and supplying them into anengine exhaust pipe.
 10. A system for heat recovery for an internalcombustion engine, comprising a heat exchanger including a plurality ofheat exchanging elements; means for introducing a fluid into said heatexchanging element for heating the first fluid, and withdrawing thefirst heated fluid from the heat exchanger elements; and supplying atleast one second fluid which is used during the operation of theinternal combustion engine and is heated, so as to flow outside and incontact with said heat exchanging elements to transfer heat throughwalls of said heat exchanging element from said second fluid to saidfirst fluid.
 11. A system as defined in claim 10, wherein said means forsupplying the second fluid includes means for supplying a coolant usedduring the operation of the internal combustion engine.
 12. A system asdefined in claim 10, wherein said means for supplying the second fluidincludes means for supplying a lubricant used during the operation ofthe internal combustion engine.
 13. A system as defined in claim 10,wherein said means for supplying the second fluid includes means forsupplying an exhaust produced during the operation of the internalcombustion engine.
 14. A system as defined in claim 10, wherein saidmeans for supplying the second fluid includes means for supplying atleast two second fluids selected from the group consisting of a coolant,a lubricant and an exhaust of the internal combustion engine.
 15. Asystem as defined in claim 10; and further comprising a catalyticmaterial applied on an outer surface of said heat exchanging elementssuch that the second fluid is brought in contact with the catalyticmaterial to cause a catalytic process and to release heat.
 16. A systemas defined in claim 10; and further comprising means for using heatreceived by the first fluid for creating a heat.
 17. A system as definedin claim 10; and further comprising means for using heat received by thefirst fluid for creating a work energy.
 18. A method as defined in claim10; and further comprising means for withdrawing crankcase fumes fromthe internal combustion engine and supplying them into an engine exhaustpipe.